Diminished luteinizing hormone pulse frequency and amplitude with aging in the male rat.

A. E. Karpas, W. J. Bremner, D. K. Clifton, R. A. Steiner, Daniel Dorsa

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

Aging in the male rat is associated with a reduction in circulating testosterone levels. One possible cause of this decline is an age-related alteration of central nervous system-mediated LH secretion. To examine the effects of age on the hypothalamo-hypophyseal system, in the absence of gonadal steroid feedback, we studied the pattern of pulsatile LH secretion in castrate male Sprague-Dawley rats, aged 3 months (young), 8 months (middle-aged), and 26 months (old). All animals were castrated, and after 3 weeks, they were implanted with indwelling atrial catheters. One day later, duplicate 25 microliters blood samples were obtained at 4-min intervals for 4 h, while the animals were awake and unrestrained. Serum levels of LH, FSH, and testosterone were measured in animals before castration, and blood LH levels were measured in the postcastration, repeated sampling studies. After castration, middle-aged and old animals exhibited significantly lower mean serum LH levels, associated with a diminished amplitude of LH secretory episodes compared to young rats. In the oldest group, LH pulse frequency was significantly lower compared to middle-aged and young animals. Since the control of LH secretory episodes resides in the central nervous system, we propose that alterations in frequency of LH pulses observed in the aged, castrate male rat are the result of a diminished functional capacity of LHRH-containing neurons or of neurotransmitters that modulate their activity in the aging brain.

Original languageEnglish (US)
Pages (from-to)788-792
Number of pages5
JournalEndocrinology
Volume112
Issue number3
StatePublished - Mar 1983
Externally publishedYes

Fingerprint

Luteinizing Hormone
Castration
Testosterone
Central Nervous System
Hypothalamo-Hypophyseal System
Sampling Studies
Indwelling Catheters
Serum
Gonadotropin-Releasing Hormone
Neurotransmitter Agents
Sprague Dawley Rats
Steroids
Neurons
Brain

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

Cite this

Karpas, A. E., Bremner, W. J., Clifton, D. K., Steiner, R. A., & Dorsa, D. (1983). Diminished luteinizing hormone pulse frequency and amplitude with aging in the male rat. Endocrinology, 112(3), 788-792.

Diminished luteinizing hormone pulse frequency and amplitude with aging in the male rat. / Karpas, A. E.; Bremner, W. J.; Clifton, D. K.; Steiner, R. A.; Dorsa, Daniel.

In: Endocrinology, Vol. 112, No. 3, 03.1983, p. 788-792.

Research output: Contribution to journalArticle

Karpas, AE, Bremner, WJ, Clifton, DK, Steiner, RA & Dorsa, D 1983, 'Diminished luteinizing hormone pulse frequency and amplitude with aging in the male rat.', Endocrinology, vol. 112, no. 3, pp. 788-792.
Karpas AE, Bremner WJ, Clifton DK, Steiner RA, Dorsa D. Diminished luteinizing hormone pulse frequency and amplitude with aging in the male rat. Endocrinology. 1983 Mar;112(3):788-792.
Karpas, A. E. ; Bremner, W. J. ; Clifton, D. K. ; Steiner, R. A. ; Dorsa, Daniel. / Diminished luteinizing hormone pulse frequency and amplitude with aging in the male rat. In: Endocrinology. 1983 ; Vol. 112, No. 3. pp. 788-792.
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